In recent years, from the demand for small sized, thin and high performance electronic devices, many flip-chip mounted semiconductor devices are being implemented. In a flip-chip mounting, metallic protrusions referred to as bumps of solder, Au, or the like, formed on an electrode of an LSI chip, and electrodes of a substrate are bonded by heating and/or pressurizing, and with an object of improving mechanical strength and protecting from moisture, a gap between the LSI chip and the substrate is sealed by resin. Furthermore, as a process that does not require the application of heat or pressure, technology is being developed, which is referred to as normal temperature bonding or surface activated bonding, and in which the electrode surface, after being flattened, is cleaned by an Ar atom beam or the like, and bonding is performed.
As a patent document disclosing these, Patent Document 1 discloses technology of mounting without imposing a temperature or load in a bonding process, and not requiring sealing by resin (FIG. 9). Furthermore, Patent Document 2 discloses technology, with regard to electromagnetic noise cited as a problem when performing flip-chip mounting, of forming a ground layer on a flat surface the same as an electrode surface, and bonding together with an electrode joint (FIG. 10).
[Patent Document 1]
    JP Patent No. 4095049[Patent Document 2]    JP Patent Kokai Publication No. JP-P2000-299379A